Fix WebGL book SSAO occlusion

public/js/webgl-book-lab.js

@@ -506,6 +506,7 @@ function configureScenePostprocessing() {
     composer.addPass(sceneRenderPass);
 
     sceneAoPass = new SSAOPass(scene, camera, 1, 1, 64);
+    sceneAoPass.normalMaterial.side = THREE.DoubleSide;
     sceneAoPass.kernelRadius = 0.48;
     sceneAoPass.minDistance = 0.00025;
     sceneAoPass.maxDistance = 0.065;
@@ -1198,9 +1199,6 @@ function buildBook() {
     });
     currentProceduralBookModel = proceduralBook.model;
     book.add(proceduralBook.group);
-    proceduralBook.group.traverse((object) => {
-        if (object.isMesh) aoExcludedObjects.add(object);
-    });
 }
 
 function setReadingProgress(value) {
@@ -1448,7 +1446,6 @@ function setActivePageGeometry(flip, surface) {
         flip.mesh.receiveShadow = false;
         flip.mesh.userData.bookPart = 'flippingPage';
         flip.mesh.userData.isProceduralBookMesh = true;
-        aoExcludedObjects.add(flip.mesh);
         book.add(flip.mesh);
         return;
     }